Telephone-exchange system



H. P. CLAUSEN AND C. L. GOODRUM.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JUNE 5. 1919.

Patented Aug. 9,, 1921.,

fiewryFC/ausew QN l lessees.

- HENRY P. CLAUSEN, OE MOUNT VERNON, AN D CHARLES L. GOODR'UM, 015 NEWY0,

N. Y., ASSIGNORS 'IO WESTERN ELECTRIC COMPANY, OF NEW Y0, N. Y., A COR-PO'IION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Aug, 9, 1921.

Application filed June 5, 1919. Serial No. 302,031.

To all whom it may concern.

and CHARLES L.- GOODRUM, citizens of the United States, residing atMount Vern0n,.

in the county of Westchester and State of New York, and at New York, inthe county of New York and State of New York, re-

spectively, have invented certain new and useful Improvements 1nTelephone Exchange Systems, of which the followmg 1s a full, clear,concise, and exact description.

This invention relates to machine switching telephone systems, andparticularly to such systems in which speclal service features areincluded.

The object of this invention is to provlde an arrangement whereby specal servlce designed to expedite the work 1n a commercial otfice may begiven.

A feature of the invention is the manner in which several telephonelines are multipled in the terminals. of a connector switch, the samelines arranged in several groups, the several lines appearing in adifierent order in each group.

Let us assume the case of the office of the patent department of a reattelephone manufacturing company. he attorney S has charge of a group ofattorneys all working on the prosecution of ap lications relating toautomatic telephony. one of the attorneys reporting to S, is working onapplications dealing with power drlve systems, while another attorney His working on applications dealing with step-by-step systems.

A party desiring general informatlon about automatic telephone systemsmay call S, but finds his line busy. K, however, could probably give thedesired information, and it would expedite matters if he could beautomatically reached under the circumstances. Furthermore, both S and Kmight be busy, in which case H might be able to give the desiredinformation or at least tell the calling party that he could procuresuch information and would call him back. In this case it would expeditematters if H could be automatically reached. In another case, the partycalling for specific information on power drive systems in calling Kmight find Ks line busy, but I-I might be able to help out, or in casehe too is busy,

. might be able to give the desired informa- Be it known that we, HENRYP. CLAUsEN\t 1on.

In a third case, a party calling for speclfic information onstep-by-step systems in calling I-I might find his line busy. It wouldbe expedient in that case to have the call automatically directed to .Sor to K in turn.

A feature of the invention is therefore the provision of means forcalling any desired line of a group of lines, and in case that such lineis busy, to automatically direct the call to other lines of the groupleading in turn to parties next in ability to give the desiredinformation or subordinate to the first for the particular servicedesired. This and other features of the invention will more fully appearin the following description and the appended claims.

Special notice is directed to the arrange ment of the called lines. Thegrou of called lines for the use of S, K and are connected to severalgroups of terminals in the connector switch in different orders. In thefirst Igroup they appear in the order S, K and in the second grou K, Hand S, and in the third group HE S- and K. Thus, any one of the threelines may be reached by a directive setting of the connector switch. Ifthe line thus selected is busy, the connector is arranged toautomatically select one of the others.

It is not necessary that the groups of called lines be arranged as shownin the drawing, that is, all on one level, but might be widelyseparated, their positions depending on the numbers of the first line ineach group. In the figure of the drawin a calling substation isindicated at the le t-hand side, the circuit of a trunk-huntingconnector is diagrammatically shown at the center, and the multipledarrangement of three called lines with their connections to theterminals of a connector switch is shown at the righthand upper corner.

Let us assume that the calling party, as in the case assumed, wishesspecificinformation on a certain question dealing with power driveautomatic telephone systems, and therefore makes a call to Ks line. Thecalling party removes his receiver at the substation 1, whereupon he isconnected in any well-known manner to the connector switch 2. Upon theseizure of this connector switch, the line relay 3 is energized andattracts its armature. A circuit is thereupon established from ground,the armature and front contact of relay 3, the armature and contact ofrelay 4, the winding of relay 5, to battery and ground. Relay 5 1senergized and attracts its armatures. The calling arty now manipulateslllS dial 6 to directively set the brushes 7, 8 and 9 on the terminalsof Ks line. The first ser1es of impulses transmitttd by the dlal 6conslsts of a series of interruptions in the line circuit, whereby thearmature of relay 3 is yibrated. Upon each retraction thereof, a 01rcuitis completed from ground, the armature and back contact of relay 3,right-hand armature and front contact of relay 5, the side switch arm 10and its first position contact, the primary magnet 11, to battery, andground, whereby the prlmary magnet acts to ste the brushes 7 8 and 9 tothe level in which Ks line appears. This series of impulses transmittedto the rimary magnet 11 also energizes the leftand winding of escapemagnet 12, whereby it attractsits armature and retains it in thisposition until the end of this series of impulses. When these impulseshave been all transmitted,

therelay 3 retains its armature in the actuated position and allows theescape magnet to, deenergize, the side switch wipers are passed intotheir second position.

The subscriber at substation 1 nowmanipulates his dial 6 to set thebrushes 7, 8 and 9 on the terminals of Ks line. These terminals areshown as 13, 14 and 15. In the same manner that the primary magnet wasactuated, the secondary magnet 16 is now actuated, and the'brushes 7, 8and 9 areset on the terminals 13, 14 and 15.

We will assume that Ks line is busy. That means that a round will befound on the terminal 15, w ereupon a circuit will be completed fromground, terminal 15, brush 9, side switch wiper 17 and its secondposition contact,.and as soon as the armature 18 has been released,through the contact and armature 18, the left-hand winding of escapemagnet 12, to battery and ground. The escape magnet 18 is arranged inthe same manner as the side-switch magnet shown in the patent toGoodrum, No.

1,202,281, granted Oct. 24, 1916, in such a" manner that the armature 18will make its contact before the escape magnet allows the side-switchwipers to pass into their next position. Hence, as soon as the armature18 completes the circuit just described, the escape magnet will again beenergized. Since the side-switch wipers are in their second position,the closure of this circuit will also close a circuit through thesideswitch wiper 10 and the secondary magnet 16, whereby the brushes 7,8 and 9 will be stepped on to the next set of contacts. the lineconnected to this set of contacts is also busy, the brushes will in thesame manner'be stepped on to the set of contacts 19, 20 and 21, whichlead, as in the case assumed, to Ss line. Ss line being idle, no groundwill be found on the contact 21, and hence upon the release of thearmature 18, the escape magnet 12 will not again be energized and willcause the passage of the sideswitch wipers into their third position.

In this position, ringing current is supplied through the windings ofthe relay 4, the

side-switch wipers 22 and 2.3, the brushes 7 and 8, the terminals 19 and20 to the call bell of the substation 24. Uponthe response of the calledsubscriber, relay 4 will be energized sufliciently to actuate itsarmature, which opens a short circuit over the righthand winding ofmagnet 12 and includes it in the circuit of relay 5. Magnet 12 will beenergized in this circuit, and upon its energization will pass theside-switch wipers into their fourth position, whereupon conversationmay take place.

When the calling and called subscribers replace their receiver's ontheir hooks, relays 3 and 25 will become deenergized, and relay 5 will,in response to the deenergization of relay 3, also become denergized.Thereupon, a circuit will be established from ground, the armature andback contact of relay 3, the right-hand armature and back contact ofrelay 5, the left-hand armature and back contact of relay 25, left-handarmature and contact of relay 5, right-hand armature and contact ofrelay 25, the primary off-normal contact 26, winding of release magnet27, to battery and ground, which will cause the release of theconnection in thewell-known manner.

Should all of the lines of the group have been busy, the brushes 7 8 and9 would have passed to the set of busy contacts 28, 29 and 30, and theside-switch wipers 22 and 23 pass into their third position as describedIn this position a circuit would have been established from ground, thesecondary winding of BZ, contact 28, brush 7 sideswitch wiper 22 in itsthird position, lefthand winding of relay 4, through a source of ringingcurrent, and the current traveling over this path would have beensuflicient'to energize the relay 4', whereby the side-switch wiperswould have been passed into their fourth position as has been described.In this position the tone from the source BZ would have been transmittedto the calling substation and the subscriber there notified that alllines, over which he might get the desired information were busy, and hewould thereupon hang up and release the. connection.

What is claimed is:

1. In a telephone system, line terminals,

a group of lines terminating in several groups of terminals in variousorders of subordinatioma calling line, and means for extending saidcalling line to any one of said lines in said group and responsive tothe busy condition of said line to automatically extend said callingline to the next in turn subordinate line.

2. In a selecting system, circuit terminals, a group of circuitsterminating in several groups of terminals in various orders ofsubordination, means for selecting any one of said circuits, and meansfor automatically selecting a subordinate circuit if the first oneselected is busy.

3. In a selecting system, circuit terminals, a group of circuitsterminating in several groups of terminals in various orders ofsubordination, and means for selecting any one of said circuits and forthereafter automatically selecting a subordinate circuit.

In Witness whereof, We hereunto subscribe our names this 28th day ofMay, A. D. 1919.

HENRY P. CLAUSEN. CHARLES L. GOODRUM.

